casper.test.begin('The heading exists', 1, function suite(test) {
    casper.start('https://www.baidu.com', function() {
        test.assertExists('div.s_form');
        test.assertSelectorHasText('div.s_form', 'Hello');
        test.assertVisible('footer');
    }).run(function() {
        test.done();
    });
});